Reflective type screen using a spacer layer

ABSTRACT

A reflective type screen using a spacer layer and that includes a light blocking layer blocking an incident light, a reflective layer formed on the light blocking layer to reflect the incident light, a diffusion layer formed on the reflective layer to diffuse the incident light, and at least one spacer layer formed between the reflective layer and the diffusion layer to have a refractive index differing from that of an adjacent layer to refract the incident light.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the U.S. Provisional ApplicationNo. 61/118,418, filed on Nov. 26, 2008, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a reflective type screen, and moreparticularly, to a reflective type screen using a spacer layer.

2. Discussion of the Related Art

Recently, entering upon the 21^(st) century for the era of advancedinformation, research and development of new displays become moreimportant. And, the request and demand for a large-scale display israpidly rising.

Yet, the drop in prices of a large-scale display may not meet the levelwanted by consumers.

A 42-inch display is approaching it popularization and a fall in pricesof a 50-inch display is increasing. Yet, a flat panel display over 70inches suitable for a home theater implementation is still far away frompopularization due to its price too high for a general consumer topurchase.

On the contrary, a projection TV having good performance in aspect ofprice per screen size is more disadvantageous in volume and imagequality than a flat panel display and is not popular anymore.

Currently, a front projector having its own market for a mania groupjust can be installed by hanging its screen on a wall and can solve theproblem of the disadvantages of the projection TV in aspect of volume.

Although installation of the front projector is not easy and aprojection distance has to be secured, a development of a product havinga considerably short projection distance is ongoing. Moreover, aconsumer-specific building design is available. Hence, the problemcaused by transmission and power lines can be solved by built-inconnection.

And, this problem can be also solved by the development of the wirelesstransmission technology.

Even if the above mentioned problems are solved, the projector is stillinferior to the flat panel display in aspect of image quality.Considering the research and development of the projector are set towardLED and laser systems, brightness of the projector is much poorer thanthat of the conventional lamp system. Thus, the problems of the imagequality and brightness become more important issues.

Accordingly, the demand for a solution of a contrast ratio problemaffecting the brightness and image quality, and more particularly, theimage quality is rising.

However, it seems that the enhancement of the project is unable to solvethe above mentioned problems. So, many efforts are made to discover away for the solution from a screen that is a final interface contactingwith a user.

Recently, since many attempts to increase the brightness and contrastratio of the screen have been made in various ways, various kinds ofsurface treatments and stacked layer structures are developed to meet aprescribed level. But, they still fail to reach a level for consumer'ssatisfaction. Specifically, many parts still need to be enhanced to copewith an LED or Laser projector.

In order to improve a brightness, image quality and viewing angle of ascreen, various kinds of optical processing are performed on the screenin general. Specifically, it is attempted to obtain specific performancein a manner of controlling diffusion, reflection and absorption of lighton a screen surface by various structures and methods.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a reflective typescreen that substantially obviates one or more problems due tolimitations and disadvantages of the related art.

An object of the present invention is to provide a reflective typescreen, by which a brightness, image quality and viewing angle can beenhanced in a manner of increasing diffusion of light using at least onespacer layer.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, areflective type screen according to the present invention includes alight blocking layer blocking an incident light, a reflective layerformed on the light blocking layer to reflect the incident light, adiffusion layer formed on the reflective layer to diffuse the incidentlight, and at least one spacer layer formed between the reflective layerand the diffusion layer, the at least one spacer layer configured tohave a refractive index differing from that of an adjacent layer torefract the incident light.

Preferably, a refractive index difference between the at least onespacer layer and the adjacent layer is 0.01˜1.

Preferably, the refractive index of the at least one spacer layer isgreater than that of the adjacent layer.

Preferably, the at least one spacer layer includes either an air or atransparent film.

More preferably, the transparent film includes at least one selectedfrom the group consisting of a scattering particle for scattering theincident light and a coloring agent for absorbing the incident light inpart.

More preferably, a multitude of projections are formed on either a topor bottom surface of the transparent film.

In another aspect of the present invention, a reflective type screenincludes a light blocking layer blocking an incident light, a reflectivelayer formed on the light blocking layer to reflect the incident light,first and second diffusion layers formed on the reflective layer todiffuse the incident light, and at least one spacer layer formed betweenthe first and second diffusion layers to have a refractive indexdiffering from that of each of the first and second diffusion layers torefract the incident light.

Preferably, a refractive index difference between the spacer layer andthe first diffusion layer or between the spacer layer and the seconddiffusion layer is 0.01˜1 and a refractive index of the spacer layer isgreater than that of each of the first and second diffusion layers.

Preferably, the spacer layer includes either a single layer formed of anair or a transparent film or a multi-layer including a first layerformed of the air and a second layer formed of the transparent film.

In another aspect of the present invention, a reflective type screenincludes a light blocking layer blocking an incident light, a reflectivelayer formed on the light blocking layer to reflect the incident light,a diffusion layer formed on the reflective layer to diffuse the incidentlight, and first and second spacer layers formed between the reflectivelayer and the diffusion layer, each having a refractive index differingfrom that of an adjacent layer to refract the incident light. In thiscase, the first spacer layer is formed of an air and the second spacerlayer is formed of a transparent film.

In a further aspect of the present invention, a reflective type screenincludes a light blocking layer blocking an incident light, a reflectivelayer formed on the light blocking layer to reflect the incident light,a second film formed on the reflective layer, the second film includinga second diffusion layer diffusing the incident light and a secondspacer layer having a refractive index differing from that of the seconddiffusion layer to refract the incident light, and a first film formedon the second film, the first film including a first diffusion layerdiffusing the incident light and a first spacer layer having arefractive index differing from that of the first diffusion layer.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a cross-sectional diagram of a reflective type screenaccording to a first embodiment of the present invention;

FIG. 2 is a cross-sectional diagram of a reflective type screenaccording to a second embodiment of the present invention;

FIG. 3 is a cross-sectional diagram of a reflective type screenaccording to a third embodiment of the present invention;

FIG. 4 is a cross-sectional diagram of a reflective type screenaccording to a fourth embodiment of the present invention; and

FIG. 5 is a cross-sectional diagram of a reflective type screenaccording to a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

With various modifications and alterations of the present invention,specific embodiments of the present invention are exemplarily shown inthe drawings and will be explained in detail in the followingdescription. It is not intended to limit the present invention in aspecific form disclosed in the specification. Instead, the presentinvention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents.

FIG. 1 is a cross-sectional diagram of a reflective type screenaccording to a first embodiment of the present invention.

Referring to FIG. 1, a reflective type screen according to a firstembodiment of the present invention can mainly include a light blocklayer 100, a reflective layer 110, a diffusion layer 120 and a spacerlayer 130.

In this case, the light blocking layer plays a role in blocking anincident light or can play a role in absorbing the incident light.

The light blocking layer 100 can play a role as a deposition mothermaterial of the reflective layer 110 and can be formed of one ofpolyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP),polyvinylchloride (PVC), etc.

In order to increase a contrast ratio of image by absorbing an externallight, the light blocking layer 100 can be formed of a non-transparentplastic film, plastic sheet or glass of black, gray or one of other darkcolor series.

In this case, if the light blocking layer 100 is formed of plastic, itis able to use acryl resin or polycarbonate resin. In order to implementa dark color, the light blocking layer 100 can be formed in a manner ofspreading a dark pigment into plastic or tinting a dark pigment onplastic.

The reflective layer 110 is formed on the light blocking layer 100 andplays a role in reflecting an incident light.

The reflective layer 110 can be formed of one of such a metal sheethaving a high glossy reflective property as Al, Ag, Fe and the like, ametal coated reflective film including a plastic film and such a metalcoated on the plastic film as Au, Ag, Al, stainless steel and the like,a metal coated reflective glass including a glass and a metal coated onthe glass, a mirror glass and the like.

In this case, a light reflexibility of the light reflective layer rangesbetween 10 and 95% and can be determined according to a thickness of thespacer layer 120 or a light absorptivity of the spacer layer 120.

For instance, if the thickness of the spacer layer 120 is 0.01˜149 μm ora light absorptive coloring agent is not contained in the spacer layer120, the light reflexibility of the reflective layer 110 ranges between10˜30%. For another instance, if the thickness of the spacer layer 120is 150 μm˜1 mm or a light absorptive coloring agent is contained in thespacer layer 120, the light reflexibility of the reflective layer 110can range between 31˜95%.

The spacer layer 120 can be provided as a single layer or a multi-layerbetween the reflective layer 110 and the diffusion layer 130. And, thespacer layer 120 can have a refractive index different from that of anadjacent layer to enable an incident light to be refracted.

In particular, the spacer layer 120 can have a refractive indexdifferent from that of the reflective layer 110 or the diffusion layer130 adjacent to the spacer layer 120.

Preferably, a refractive index difference between the spacer layer 120and the reflective layer 110 or the diffusion layer 130 adjacent to thespacer layer 120 is set to 0.01˜1.

The reason why the refractive index difference between the spacer layer120 and the adjacent layer is set to 0.01˜1 is because a brightness,image quality and viewing angle can be enhanced by further increasingthe diffusion of the incident light.

If the refractive index difference between the spacer layer 120 and theadjacent layer is set to a value equal to or smaller than 0.01, it isunable to attain the object of the present invention. And, it is alsodifficult to fabricate a reflective type screen having a refractiveindex difference set to a value equal to or greater than 1.

Preferably, the refractive index of the spacer layer 120 is set greaterthan that of the reflective layer 110 or the diffusion layer 130adjacent to the spacer layer 120.

And, the spacer layer 120 can include air or a transparent film.

In this case, the transparent film can include one of polyethylene (PE),polyethylene terephthalate (PET), polypropylene (PP), polyvinylchloride(PVC), ethylene vinyl alcohol (EVA), urethane resin, polycarbonate (PC),polymethylmethacrylate (PMMA), etc.

The transparent film can include at least one of a scattering particlefor scattering an incident light and a coloring agent for absorbing theincident light in part.

In this case, a diameter of the scattering particle is 1˜200 μm andpreferably has 1˜50 parts by weight in a total weight 100 of thetransparent film.

If the diameter of the scattering particle is equal to or grater than200 μm, a viewing angle is degraded. If the diameter of the scatteringparticle is equal to or smaller than 1 μm, a luminance may be degraded.If a content of scattering particles is smaller than about 1 part byweight or equal to or greater than 50 parts by weight, the luminance andviewing angle can be degraded.

The scattering particle is formed of one of such an inorganic materialas silica, zirconia, glass and the like and such an organic material asacryl resin, urethane resin, vinyl chloride resin and the like or can beformed of a mixture thereof.

The coloring agent includes black dyes or pigments. The coloring agentpreferably has 1˜10 parts by weight in total weight of 100 parts byweight of the transparent film.

The coloring agent reduces a reflective quantity of an external light byabsorbing light, thereby improving a contrast of image. Therefore, thecoloring agent can use such black dyes or pigments as carbon black.

If a content of the coloring agent is equal to or smaller than 1 part byweight, the contrast can be degraded. If a content of the coloring agentis greater than 10 parts by weight, the luminance can be degraded.

Meanwhile, the spacer layer 120 can be formed 0.01 μm˜1 mm thick. Incase that the spacer layer 120 includes the transparent film, it ispreferably formed 0.01 μm 1 mm thick. In case that the spacer layer 120is formed of air, it can be formed 0.001 μm 1 mm thick.

In case that the thickness of the spacer layer 120 is equal to smallerthan 0.001 μm, the luminance and viewing angle are not enhanced. In casethat the thickness of the spacer layer 120 is equal to or greater than 1mm, a manufacturing cost is raised and the corresponding fabrication maybecome difficult.

In order to improve a viewing angle by increasing diffusion of light, amultitude of projections can be further formed on either a top or bottomsurface of the spacer layer 120 including the transparent film.

In this case, a height of each of the projections is preferably set to70 μm˜0.5 mm. A gap between the projections can be preferably set to0.001˜0.1 mm.

If the projection's height or gap of the spacer layer 120 deviates fromthe above range, the diffusion of light is degraded. Hence, the viewingangle may not be enhanced.

And, the gap between the projections can be filled with air.

Therefore, the transparent film and the air, which differ from eachother in a refractive index, can coexist on a boundary between thespacer layer 120 having the projections and an adjacent layer.

Meanwhile, the diffusion layer 130 is formed on the reflective layer 110and is able to play a role in diffusing an incident light.

In this case, the diffusion layer 130 can be formed of one ofpolyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP),polyvinylchloride (PVC), ethylene vinyl alcohol (EVA), urethane resin,polycarbonate (PC), polymethylmethacrylate (PMMA), etc. or a mixturethereof. And, the diffusion layer 130 can further include at least oneof a scattering particle for scattering an incident light and a coloringagent for absorbing the incident light in part.

Moreover, a multitude of projections can be further formed on a surfaceof the diffusion layer 130 on which a light is externally incident.

In this case, a height of each of the projections is preferably set to70 μm˜0.5 mm. A gap between the projections can be preferably set to0.001˜0.1 mm.

FIG. 2 is a cross-sectional diagram of a reflective type screenaccording to a second embodiment of the present invention.

Referring to FIG. 2, a reflective type screen according to a secondembodiment of the present invention includes a light block layer 100, areflective layer 110 on the light blocking layer 100, a second diffusionlayer 130 b on the reflective layer 110, a spacer layer 120 on thesecond diffusion layer 130 b and a first diffusion layer 130 a on thespacer layer 120.

In this case, the spacer layer 120 can be formed between the firstdiffusion layer 130 a and the second diffusion layer 130 b. In order torefract an incident light, a refractive index of the first diffusionlayer 130 a can be set different from that of the second diffusion layer130 b.

In particular, a refractive index difference between the spacer layer120 and the first diffusion layer 130 a or a refractive index differencebetween the spacer layer 120 and the second diffusion layer 130 b isabout 0.01˜1. And, the refractive index of the spacer layer 120 can beset greater than that of the first/second diffusion layer 130 a/130 b.

And, the spacer layer 120 can be formed of air or a transparent film.

For instance, each of the first and second diffusion layers 130 a and130 b is formed of the transparent film and the spacer layer 120 formedbetween the first and second diffusion layers 130 a and 130 b can beformed of air.

In this case, the spacer layer 120 formed of the air is formed 0.001μm˜1 mm thick. And, each of the first and second diffusion layers 130 aand 130 b can be formed of one of polyethylene (PE), polyethyleneterephthalate (PET), polypropylene (PP), polyvinylchloride (PVC),ethylene vinyl alcohol (EVA), urethane resin, polycarbonate (PC),polymethylmethacrylate (PMMA), etc. or a mixture thereof.

Alternatively, the first diffusion layer 130 a, the second diffusionlayer 130 b and the spacer layer 120 can include transparent films. And,they can be formed of one of polyethylene (PE), polyethyleneterephthalate (PET), polypropylene (PP), polyvinylchloride (PVC),ethylene vinyl alcohol (EVA), urethane resin, polycarbonate (PC),polymethylmethacrylate (PMMA), etc. or a mixture thereof.

In case that the spacer layer 120 is formed of the transparent film, thespacer layer 120 is preferably formed of a material having a refractiveindex differing from that of each of the first and second diffusionlayers 130 a and 130 b.

Since the second embodiment of the present invention differs from thefirst embodiment of the present invention only in that the diffusionlayer is additionally included, its details are omitted from thefollowing description.

FIG. 3 is a cross-sectional diagram of a reflective type screenaccording to a third embodiment of the present invention.

Referring to FIG. 3, a reflective type screen according to a thirdembodiment of the present invention includes a light blocking layer 100,a reflective layer 110 on the light blocking layer 100, a second spacerlayer 120 b on the reflective layer 110, a first spacer layer 120 a onthe second spacer layer 120 a and a diffusion layer 130.

In this case, the first and second spacer layers 120 a and 120 b can beformed between the reflective layer 110 and the diffusion layer 130.And, each of the first and second spacer layers 120 a and 120 b can havea refractive index differing from that of each of the reflective layer110 and the diffusion layer 130.

In particular, a refractive index difference between each of the firstand second spacer layers 120 a and 120 b and the reflective layer 110 ora refractive index difference between each of the spacer layers 120 aand 120 b and the diffusion layer 130 is set to 0.01˜1. And, therefractive index of each of the first and second spacer layers 120 a and120 b can be greater than that of each of the reflective layer 110 andthe diffusion layer 130.

The first spacer layer 120 a and the second spacer layer 120 b candiffer from each other in a refractive index. Preferably, the refractiveindex of the firs spacer layer 120 a is set greater than that of thesecond spacer layer 120 b, by which the present invention isnon-limited.

In this case, each of the first and second spacer layers 120 a and 120 bcan be formed of air or a transparent film. Preferably, the first andsecond spacer layers 120 a and 120 b are formed of different materials,respectively, by which the present invention is non-limited.

For instance, if the first spacer layer 120 a is formed of the air, thesecond spacer layer 120 can be formed of the transparent film.

In this case, the second spacer 120 b formed of the transparent film ispreferably formed 150 μm˜1 mm thick. And, the first spacer layer 120 aformed of the air can be formed 0.001 μm˜1 mm thick.

For another instance, if the first spacer layer 120 a is formed of thetransparent film, the second spacer layer 120 can be formed of the air.

In this case, the first spacer 120 a formed of the transparent film ispreferably formed 150 μm˜1 mm thick. And, the first spacer layer 120 aformed of the air can be formed 0.001 μm˜1 mm thick.

In this case, the refractive index difference between the first spacerlayer 120 a and the second spacer layer 120 b can be set to 0.01˜1.

In particular, the refractive index difference between the second spacerlayer 120 b and the reflective layer 110 or the refractive indexdifference between the second spacer layer 120 b and the first spacerlayer 120 a is 0.01˜1. The refractive index difference between the firstspacer layer 120 q and the second spacer layer 120 b or the refractiveindex difference between the first spacer layer 120 a and the diffusionlayer 130 can be set to 0.01˜1.

Since the third embodiment of the present invention differs from thefirst embodiment of the present invention only in that the spacer layeris additionally included, its details are omitted from the followingdescription.

Occasionally, a plurality of spacer layers (at least two spacer layers)can be provided between the diffusion layer and the reflective layer.

FIG. 4 is a cross-sectional diagram of a reflective type screenaccording to a fourth embodiment of the present invention.

Referring to FIG. 4, a reflective type screen according to a fourthembodiment of the present invention includes a light blocking layer 100,a reflective layer 110 on the light blocking layer 100, a seconddiffusion layer 130 b on the reflective layer 110, a second spacer layer120 b on the second diffusion layer 130 b, a first spacer layer 120 a onthe second spacer layer 120 b and a first diffusion layer 130 a on thefirst spacer layer 120 a.

In this case, the first and second spacer layers 120 a and 120 b can beformed between the first diffusion layer 130 a and the second diffusionlayer 130 b. And, each of the first and second spacer layers 120 a and120 b can have a refractive index differing from that of each of thefirst diffusion layer 130 a and the second diffusion layer 130 b.

In particular, a refractive index difference between each of the firstand second spacer layers 120 a and 120 b and the first diffusion layer130 a or a refractive index difference between each of the spacer layers120 a and 120 b and the second diffusion layer 130 is set to 0.01˜1.And, the refractive index of each of the first and second spacer layers120 a and 120 b can be greater than that of each of the first and seconddiffusion layers 130 a and 130 b.

The first spacer layer 120 a and the second spacer layer 120 b candiffer from each other in a refractive index. Preferably, the refractiveindex of the first spacer layer 120 a is set greater than that of thesecond spacer layer 120 b, by which the present invention isnon-limited.

In this case, each of the first and second spacer layers 120 a and 120 bcan be formed of air or a transparent film. Preferably, the first andsecond spacer layers 120 a and 120 b are formed of different materials,respectively, by which the present invention is non-limited.

For instance, if the first spacer layer 120 a is formed of the air, thesecond spacer layer 120 can be formed of the transparent film.

In this case, the second spacer layer 120 b formed of the transparentfilm is preferably formed 150 μm˜1 mm thick. And, the first spacer layer120 a formed of the air can be formed 0.001 μm˜1 mm thick.

For another instance, if the first spacer layer 120 a is formed of thetransparent film, the second spacer layer 120 can be formed of the air.

In this case, the first spacer 120 a formed of the transparent film ispreferably formed 150 μm˜1 mm thick. And, the second spacer layer 120 bformed of the air can be formed 0.001 μm˜1 mm thick.

In this case, the refractive index difference between the first spacerlayer 120 a and the second spacer layer 120 b can be set to 0.01˜1.

In particular, the refractive index difference between the second spacerlayer 120 b and the second diffusion layer 130 b or the refractive indexdifference between the second spacer layer 120 b and the first spacerlayer 120 a is 0.01˜1. The refractive index difference between the firstspacer layer 120 q and the second spacer layer 120 b or the refractiveindex difference between the first spacer layer 120 a and the firstdiffusion layer 130 a can be set to 0.01˜1.

Since the fourth embodiment of the present invention differs from thefirst embodiment of the present invention only in that the spacer layerand the diffusion layer are additionally included, its details areomitted from the following description.

Occasionally, a plurality of spacer layers (at least two spacer layers)can be provided between the first and second diffusion layers.

FIG. 5 is a cross-sectional diagram of a reflective type screenaccording to a fifth embodiment of the present invention.

Referring to FIG. 5, a reflective type screen according to a fifthembodiment of the present invention includes a light blocking layer 100,a reflective layer on the light blocking layer 100, a second spacerlayer 120 b on the reflective layer 110, a second diffusion layer 130 bon the second spacer layer 120 b, a first spacer layer 120 a on thesecond diffusion layer 130 b, and a first diffusion layer 130 a on thefirst spacer layer 120 a.

In this case, the first spacer layer 120 a is formed between the firstdiffusion layer 130 and the second diffusion layer 130 b and can have arefractive index differing from that of each off the first and seconddiffusion layers 10 a and 130 b.

Moreover, the second spacer layer 120 b is formed between the reflectivelayer 110 and the second diffusion layer 130 b and can have a refractiveindex differing from that of each of the reflective layer 110 and thesecond diffusion layer 130 b.

In particular, a refractive index difference between the first spacerlayer 120 a and the first diffusion layer 130 a or a refractive indexdifference between the first spacer 120 a and the second diffusion layer130 b is 0.01˜1. And, a refractive index of the first spacer layer 120 acan be greater than that of each of the first and second diffusionlayers 130 a and 130 b.

In particular, a refractive index difference between the second spacerlayer 120 b and the reflective layer 110 or a refractive indexdifference between the second spacer 120 b and the second diffusionlayer 130 b is 0.01˜1. And, a refractive index of the second spacerlayer 120 b can be greater than that of each of the reflective layer 110and the second diffusion layers 130 b.

The first spacer layer 120 a and the second spacer layer 120 b candiffer from each other in a refractive index. Preferably, the refractiveindex of the first spacer layer 120 a is set greater than that of thesecond spacer layer 120 b, by which the present invention isnon-limited.

In this case, each of the first and second spacer layers 120 a and 120 bcan be formed of air or a transparent film. Optionally, the first andsecond spacer layers 120 a and 120 b are formed of the same material orcan be formed of different materials, respectively.

For instance, each of the first and second spacer layers 120 a and 120 bcan be formed of either the air or the transparent film.

In this case, each of the first and second spacer layers 120 b formed ofthe transparent film is preferably formed 150 μm˜1 mm thick. And, eachof the first and second spacer layers 120 a and 120 b formed of the aircan be formed 0.001 μm˜1 mm thick.

If both of the first and second spacer layers 120 a and 120 b are formedof the transparent films, respectively, an air layer can be furtherprovided between the first spacer layer 120 a and the second diffusionlayer 130 b.

In this case, the air layer is preferably formed 0.001 μm˜1 mm thick.

Since the fifth embodiment of the present invention differs from thefourth embodiment of the present invention only in that a depositingsequence of the second spacer layer and the second diffusion layer ischanged, its details are omitted from the following description.

Occasionally, a plurality of spacer layers (at least one spacer layer)can be formed between the first and second diffusion layers.Alternatively, a plurality of spacer layers (at least one spacer layer)can be formed between the second diffusion layer and the reflectivelayer.

Accordingly, a reflective type screen according to the present inventionincreases diffusion of light using at least one spacer layer, therebyenhancing brightness, image quality and viewing angle.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A reflective type screen, comprising: a light blocking layerconfigured to block an incident light; a reflective layer formed on thelight blocking layer and configured to reflect the incident light; adiffusion layer formed on the reflective layer and configured to diffusethe incident light; and at least one spacer layer formed between thereflective layer and the diffusion layer and configured to have arefractive index differing from a refractive index of an adjacent layer.2. The reflective type screen of claim 1, wherein a refractive indexdifference between the at least one spacer layer and the adjacent layeris 0.01˜1.
 3. The reflective type screen of claim 1, wherein therefractive index of the at least one spacer layer is greater than therefractive index of the adjacent layer.
 4. The reflective type screen ofclaim 1, wherein the at least one spacer layer comprises one of an airlayer and a transparent film layer.
 5. The reflective type screen ofclaim 4, wherein the transparent film comprises: at least one materialselected from the group comprising polyethylene (PE), polyethyleneterephthalate (PET), polypropylene (PP), polyvinylchloride (PVC),ethylene vinyl alcohol (EVA), urethane resin, polycarbonate (PC) andpolymethylmethacrylate (PMMA).
 6. The reflective type screen of claim 4,wherein the transparent film comprises: at least one of a scatteringparticle configured to scatter the incident light and a coloring agentconfigured to absorb the incident light in part.
 7. The reflective typescreen of claim 6, wherein a diameter of the scattering particle is1˜200 μm, and wherein the scattering particle has 1˜50 parts by weightfor 100 parts of a total weight of the transparent film.
 8. Thereflective type screen of claim 6, wherein the coloring agent comprises:one of black dye and black pigment, wherein the coloring agent has 1˜10parts by weight for 100 parts of a total weight of the transparent film.9. The reflective type screen of claim 4, wherein the at least onespacer layer comprises the air layer, and wherein a thickness of thetransparent film is 150 μm˜1 mm and a thickness of the air layer is0.001 μm˜1 mm.
 10. The reflective type screen of claim 4, furthercomprising: plural projections formed on one of a top surface and abottom surface of the transparent film.
 11. The reflective type screenof claim 10, wherein a height of one of the plural projections is 70μm˜0.5 mm, and wherein a gap between the plural projections is 0.001˜0.1mm.
 12. The reflective type screen of claim 10, wherein a space betweenthe plural projections is filled with air.
 13. A reflective type screen,comprising: a light blocking layer configured to block an incidentlight; a reflective layer formed on the light blocking layer andconfigured to reflect the incident light; first and second diffusionlayers formed on the reflective layer and configured to diffuse theincident light; and at least one spacer layer formed between the firstand second diffusion layers and having a refractive index differing froma refractive index each of the first and second diffusion layers. 14.The reflective type screen of claim 13, wherein one of a refractiveindex difference between the at least one spacer layer and the firstdiffusion layer and a refractive index difference between the at leastone spacer layer and the second diffusion layer is 0.01˜1, and whereinthe refractive index of the at least one spacer layer is greater thanthe refractive index of each of the first and second diffusion layers.15. The reflective type screen of claim 13, wherein the at least onespacer layer comprises one of: a single layer, formed of one of an airlayer and a transparent film layer; and a multi-layer including a firstlayer formed of the air layer and a second layer formed of thetransparent film layer.
 16. A reflective type screen, comprising: alight blocking layer configured to block an incident light; a reflectivelayer formed on the light blocking layer and configured to reflect theincident light; a diffusion layer formed on the reflective layer andconfigured to diffuse the incident light; and first and second spacerlayers formed between the reflective layer and the diffusion layer, eachof the first and second spacer layers having a refractive indexdiffering from a refractive index of an adjacent, wherein the firstspacer layer is formed of an air layer, and wherein the second spacerlayer is formed of a transparent film layer.
 17. The reflective typescreen of claim 16, wherein a refractive index difference between theadjacent layer and each of the first and second spacer layers is 0.01˜1,and wherein the refractive index of each of the first and second spacerlayers is greater than the refractive index of the adjacent layer.
 18. Areflective type screen, comprising: a light blocking layer configured toblock an incident light; a reflective layer formed on the light blockinglayer and configured to reflect the incident light; a second film formedon the reflective layer, the second film comprising a second diffusionlayer configured to diffuse the incident light and a second spacer layerhaving a refractive index differing from a refractive index of thesecond diffusion layer; and a first film formed on the second film, thefirst film comprising a first diffusion layer configured to diffuse theincident light and a first spacer layer having a refractive indexdiffering from a refractive index of the first diffusion layer.
 19. Thereflective type screen of claim 18, further comprising: an air layerformed between the first film and the second film.
 20. The reflectivetype screen of claim 19, wherein a thickness of the air layer is0.001˜0.01 μm.